When Mo Farah endured an interview of witless genius with the hitherto little-known LaTonya Norton, we were invited to gaze again on the wonderland of innocence that is the United States of Amnesia.

It was impossible not to feel sorry for the smile-frozen television news anchor from WDSU in New Orleans as she eked out a live studio-to-track piece with One Guy Named Mo after he'd won the local Rock 'n' Roll half-marathon in – blimey! – record time, because LaTonya gave no indication she was aware that back home he had two gold medals for running rather well at the London Olympics.

Had she forgotten? Did she know in the first place? Did Mo know she didn't know? All of this and their fixed grins threw them into a mutual pact of puzzlement, and her riveting inquiry – "Haven't you run before?" – was immediately dispatched to the library of American sporting cringe moments, which probably could not be housed in anything smaller than the Smithsonian Institution. It wasn't in the class of Larry "I wish I was 50 years younger and I'd whip your ass" Merchant's flash of late-career anger at Floyd Mayweather Jr, but only because it was saved by the interviewer's patent humanity. As she kept digging, her face remained a monument to slowly growing self-knowledge.

Although her bosses at first clumsily tried to suggest she actually did know who Mo was but kind of forgot to mention it, I bet LaTonya, caught on the hop, thought he was just some guy who'd turned up and, you know, ran 13 miles in an hour (an hour ahead of a mortal she did know, her WDSU colleague Scott Walker) and, holey moley, butter my popcorn, he won the goddam thing. Like, wow, man. How cool is that? That's a story.

However, as he had also won the Olympic 5,000m and 10,000m finals in front of a worldwide television audience of hundreds of millions only six months earlier, well, it was a bit of a stroll in the Louisiana sun.

Maybe LaTonya's not a fan. Maybe she slept through 2012. Or, poorly briefed, did she just have a brain freeze and wing it with a lot of "wows" as the suspicion grew that the guy she was talking to was one of the most famous athletes in the (rest of the) world? Probably. While the incident illustrates that the stiffly coiffed, perfectly toothed talking heads of television can be as endearingly idiotic in America as anywhere else, it also confirms a more profound truth: large parts of the United States of Amnesia still exist in a cultural vacuum. If it doesn't happen between sea and shining sea, it doesn't make the cut – well, not on WDSU last weekend.

When what might have been a minor local gaffe turned into an international guffaw, courtesy of the social media octopus at the expense of Norton and Farah (who later urged those laughing to give her a break), we saw another glimpse of the American sense of self.

Our go-to-idiots in the global village have previous, most notoriously at the London Olympics that, in fairness, might have not registered fully with Norton and millions of her compatriots because NBC reduced its core coverage to a delayed evening package. The rest of us were, well, just in the wrong time zones. It did not start well when the "anchor legend" Meredith Vieira had her own LaTonya moment during the opening ceremony, confessing she had not heard of the creator of the worldwide web, Sir Tim Berners-Lee. "Google it," advised her sidekick Matt Lauer, the irony whizzing over his neatly clipped bonce.

They also had problems with Kenneth Branagh's Isambard Kingdom Brunel, mistaking him for "a Dickensian character". It's a wonder they didn't think it was Abraham Lincoln, with that stovepipe hat and all.

Then, in place of Danny Boyle's sensitive tribute to the victims of the London terrorist attacks, NBC showed an interview with Michael Phelps. It was not Ed Morrow. Mrs Romney's horse had a better Olympics.

As for the Paralympics a couple of weeks later, NBC showed highlights on YouTube – even though the United States sent 223 athletes, the third largest team after Great Britain and China – and a 90-minute wrap-up … seven days after the event had finished.

This is not new. We all know the "World" Series in baseball is nothing of the sort, brilliant though it is. But evidence is everywhere that the rest of the planet often can go hang (arrogance not unknown on this little island for a few centuries, it should be remembered). On stages where national delineation is not always sharp – golf and tennis, most notably – American interest dips and soars. It was always one of Pete Sampras's quiet regrets that he was great in a sport that flickered only intermittently in the consciousness of his own country.

The world game, meanwhile, continues its on-off-on Stateside love affair, drawing close to ice hockey in their affections thanks to a loyal generation of soccer moms, but there will probably be no cracking of the holy trinity of NFL, MLB and NBA until the United States win football's World Cup. Even that is not a given because Americans are so attached to their gridiron, diamond and basketball court.

There is no harm in it, perhaps. Few beyond Australia's borders are much interested in AFL. You don't see kabaddi on Brighton beach. The Spaniards have their bull-fighting. Korfball is big in, who knows where? The Germans love Futsal, the French and Italians cycling. The Swiss are partial to a steep mountain with snow on it. It might be nice if everyone played cricket, but maybe it's as well they don't: the thought of losing to the United States . Well, that could never happen, could it?

But let's spare a final thought for LaTonya Norton, because there is not a soul in this business who hasn't made a howler of some sort. Last year, in front of several American colleagues, I asked the 400m runner LaShawn Merritt what were the circumstances that led to his failing a drugs test.

In the Dumb Olympics I probably am hitting the tape alongside LaTonya on this one. He had, of course, bought some penis enlargement pills over the counter at a chemists.